A throttle arrangement of the type which comprises a lever which is pivotally mounted in a bracket is normally used for propulsion of motor boats. The lever can be positioned in a neutral position, which corresponds to idling of the engine, and can also be swung in the forwards and rearwards directions in the bracket for setting a predetermined degree of throttle application in the forwards or rearwards direction of the boat. Normally, the throttle arrangement is connected to the engine by means of a wire which mechanically transfers the movements of the lever. Throttle arrangements which comprise an electrical detector by means of which the position of the lever is detected have also been developed in recent years. The position of the lever in this case can be read by a control unit. The control unit controls the operation of the boat's engine according to the set degree of throttle application.
In the field of throttle arrangements, a problem may arise due to the fact that the lever may present a relatively large stroke, i.e. it requires a large geometrical space in order to be adjustable so as to assume all positions ranging from full throttling in the forwards direction to full throttling in the rearwards direction. As a consequence, if for example the throttle arrangement is mounted close to other objects in the boat, the entire stroke of the lever cannot be used. For this reason, there is a need to be able to calibrate the setting of the throttle arrangement, for example so that full throttling is obtained when the lever is positioned halfway along its stroke. In particular, there is a demand for devices and methods for calibration of the modern type of throttle arrangement which comprises a detector which is connected to a control unit.
Another problem in connection with the above-mentioned throttle arrangement arises when the engine is idling. Depending, for example, on the type of boat which is used, how the throttle arrangement is set, and how the engine is arranged in the boat, there is a risk that resonance may arise at the idling speed of the engine. This may lead to problems in the form of heavy noise and unwanted vibrations in the boat. Consequently, there is a demand for fine tuning of the idling speed of the engine in a simple and effective manner, so that a particular setting of the throttle arrangement in the idling position always provides an idling speed at which the resonance phenomenon can be minimized.